As a semiconductor industry is highly developed, a high integration of a semiconductor device is deepened. That is, a minimum line width and thickness of layers (e.g., a conductive layer and/or a dielectric layer) of a semiconductor device becomes increasingly minute. A lot of problems may occur due to a miniature of a semiconductor device. For example, degradation of an operation speed, an increase of power consumption and/or degradation of reliability may occur. In contrast, user's requirements for an improvement of various characteristics (e.g., high speed, low power consumption and/or high reliability) of a semiconductor device are increased more and more. A lot of studies of a semiconductor device are being performed to meet the miniature and user's requirements.